It is known, as disclosed in U.S. Pat. No. 5,769,979, entitled "Rotary Air Connection for Tire Inflation System," to provide a plug which sealingly engages the inside of an axle for supporting a rotary air connection for connecting an air supply in the axle to each of the rotating tires. In such a system, the plug provides a pressure barrier to contain the pneumatic pressure within the axle. However, such a plug and other types of plugs require that the interior of the axle be machined or modified to accept such a supporting plug. This increases the expense of the installation.
The present invention is directed to the improvement in an air inflation system of a plug supporting the rotary air connection. The plug of the present invention is a press plug which sealingly engages the inside of the axle and is held in place in the axle by an interference fit without requiring additional mechanical means for locking the plug in place. The plug will provide a pressure barrier to contain the pneumatic pressure within the axle and will engage and support the rotary air connection. Therefore, the press plug of the present invention will provide a sealing pressure barrier as well as a support without requiring special machining or modification of the inside of the axle and thus is less expensive than current type plug. Thus, the present invention can be used in a standard non-modified spindle bore.